Drawbar assemblies are widely used in construction and farming industries to connect a powered work vehicle to a non-powered draft implement. In most applications, the forward portion of the drawbar assembly is rigidly connected to the rear portion of the vehicle and the draft implement is releasably connected in some manner to the rearward portion of the drawbar. This arrangement provides the flexibility of attaching a variety of draft implements to the work vehicle. In most applications, some type of quick connect device is utilized to join the draft implement to the drawbar assembly. A large number of these connecting devices use cylindrical connecting pins, which penetrate aligned holes in the drawbar and the draft implement, to complete the connection. In order to prevent damage to the draft implement and/or the work vehicle, it is very important to prevent inadvertent removal of the connecting pins. Various locking devices have been used in the past to prevent dislodgement of the connecting pins.
One type of pin locking device is disclosed in U.S. Pat. No. 3,794,357 issued to H. S. Frye on Feb. 26, 1974. In this patent, a hitch and drawbar arrangement are connected by a pin or bolt, and a lock bar prevents the connecting pin from working out of the hitch connection. Although this structure provides adequate locking of the connecting pin in a working position, the structure could not be used to lock a plurality of connecting pins in place.
Other types of pin retainers for hitch and drawbar assemblies are disclosed in U.S. Pat. No. 2,654,613 issued to C. L. Blair et al. on Oct. 6, 1953, and U.S. Pat. No. 4,394,031 issued to R. C. Barton et al. on July 19, 1983. In each of the above-noted patents, a single connecting pin or bolt is retained in a hitch connected position by a spring loaded plate member. The structure disclosed in these two patents would appear to provide sufficient locking of the single pin in each connection, but neither could be used to secure a plurality of connecting pins in a drawbar arrangement.
The present invention is directed to overcoming one or more of the problems as set forth above.